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1
21 package com.presumo.jms.message;
22
23 import java.io.DataInput  ;
24 import java.io.DataOutput ;
25 import java.io.IOException ;
26 import java.util.StringTokenizer ;
27
28
32 public final class MessageID
33 {
34
37 private final String name;
38
39
42 private final int hostUnique;
43
44
47 private final long time;
48
49
50 private final short count;
51
52
53 private final transient int hash;
54
55 private static long lastTime = System.currentTimeMillis();
56 private static short lastCount = Short.MIN_VALUE;
57 private static final Object lock = "MESSAGE_ID_LOCK";
58 private static final int memoryLocation = new Object ().hashCode();
59
60
61
65 public MessageID(String name)
66 {
67 synchronized (lock) {
68 if (lastCount == Short.MAX_VALUE) {
69 boolean done = false;
70 long currentTime = System.currentTimeMillis();
71 long diff = currentTime - lastTime;
72 if (diff <= 0) {
73 ++lastTime;
74 }
75 else {
76 lastTime = currentTime;
77 }
78 lastCount = Short.MIN_VALUE;
79 }
80 this.name = name;
81 this.hostUnique = memoryLocation;
82 this.time = lastTime;
83 this.count = lastCount++;
84 }
85
86 hash = toString().hashCode();
87 }
88
89 private MessageID(String name, int hostUnique, long time, short count)
90 {
91 this.name = name;
92 this.hostUnique = hostUnique;
93 this.time = time;
94 this.count = count;
95 hash = toString().hashCode();
96 }
97
98
102 public int hashCode()
103 {
104 return hash;
105 }
106
107 public boolean equals(Object obj)
108 {
109 if ( (obj != null) && (obj instanceof MessageID) ) {
110 MessageID id = (MessageID) obj;
111
112 return (hostUnique == id.hostUnique &&
113 time == id.time &&
114 count == id.count &&
115 name.equals(id.name) );
116 }
117 return false;
118 }
119
120 public String toString()
121 {
122 StringBuffer result = new StringBuffer ();
123 result.append(name);
124 result.append('.');
125 result.append(Integer.toString(hostUnique, 16));
126 result.append('.');
127 result.append(Long.toString(time, 16));
128 result.append('.');
129 result.append(Integer.toString(count, 16));
130 return result.toString();
131 }
132
133 public void marshal(DataOutput out) throws java.io.IOException
134 {
135 out.writeUTF(name);
136 out.writeInt(hostUnique);
137 out.writeLong(time);
138 out.writeShort(count);
139 }
140
141 public static MessageID unmarshal(DataInput in)
142 throws java.io.IOException
143 {
144 String name = in.readUTF();
145 int hostUnique = in.readInt();
146 long time = in.readLong();
147 short count = in.readShort();
148 return new MessageID(name, hostUnique, time, count);
149 }
150
151 public static MessageID unmarshal(String id)
152 {
153 StringTokenizer tokens = new StringTokenizer (id, ".");
154 String name = tokens.nextToken();
155 int hostUnique = Integer.parseInt(tokens.nextToken(), 16);
156 long time = Long.parseLong(tokens.nextToken(), 16);
157 short count = (short) Integer.parseInt(tokens.nextToken(), 16);
158 return new MessageID(name, hostUnique, time, count);
159 }
160 }
161 |
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